Swallow, the diminutive small plates restaurant on New York Avenue in Huntington, is currently closed during a major expansion and renovation. As chef-owner James Tchinnis tells it, by taking over the vacated spot next door (which used to be a dress shop), Swallow has tripled its space, transforming from a “cozy little joint” to a 3,000-square-foot restaurant with a full bar. But the small-plates menu, Tchinnis said, will remain what it was — half comprised of staples, the other half changing on a weekly basis.